Field
The present disclosure relates to methods, compositions, primers, and probes for detection of Neisseria gonorrhoeae. More specifically, the present disclosure relates detection of N. gonorrhoeae by nucleic acid-based testing methods using primers and/or probes that bind to the major outer protein opcA gene region of N. gonorrhoeae. For example, these primers and probes can be used to amplify N. gonorrhoeae nucleic acids in biological samples to determine the presence of N. gonorrhoeae or to determine the presence of N. gonorrhoeae nucleic acids.
Description of the Related Art
Neisseria gonorrhoeae is a species of non-sport forming, non-motile, gram-negative diplococci bacteria responsible for gonorrhea, a bacterial infection of the lower genital tract that is transmitted mainly by sexual contact. Symptoms of infection with N. gonorrhoeae differ depending on the site of infection, and often time, the infections are asymptomatic. Gonorrhea infection can cause conjunctivitis, pharyngitis, proctitis or urethritis, prostatitis and orchitis. Ascending infection in women can also lead to the development of acute pelvic inflammatory disease, one of the leading causes of female infertility. Gonorrhea infection can pass from an infected mother to her baby during vaginal delivery, and can result in gonococcal conjunctivitis in the newborn's eyes.
N. gonorrhoeae is closely related genetically to N. meningitidis (meningococci), the causative agent of one type of bacterial meningitis, and slightly less related to N. lactamica, an occasional human pathogen. Both N. gonorrhoeae and N. meningitidis infect humans only. There are several additional species of Neisseria that may be considered normal flora in humans including N. cinerea, N. elongata, N. flavescens, N. mucosa, N. sicca, and N. subflava. 
A number of nucleic acid amplification tests (NAATs) have been developed for clinical evaluation of N. gonorrhoeae infections, including Amplicor® CT/NG test targeting the cytosine DNA methyltransferase gene (Roche Diagnostic Corporation, Basel, Switzerland); ProbeTec™ Qx Amplification assay targeting the multi-copy pilin genes (Becton, Dickinson and Company, Franklin Lakes, N.J.); LCx® assay targeting opacity genes (opa) (Abbott Laboratories, Abbott Park, Ill.); and GenProbe APTIMA™ Combo 2 version of TMA targeting 16S ribosomal RNA gene (Gen-Probe, Incorporated, San Diego, Calif.). The NAATs have the advantage of detecting N. gonorrhoeae without pelvic examination or intraurethral swab specimen (for males) (e.g., by testing urine). However, the primers employed by certain NAATs for N. gonorrhoeae may cross-react with nongonococcal Neisseria species. Therefore, there is a need for a test that can detect N. gonorrhoeae with high sensitivity and reduced false positive results due to cross-reactivity with other bacterial species, such as Neisseria species.